The present invention relates to a blade assembly to be equipped on a motorized grader or the like.
A blade assembly illustrated in FIG. 1 is constructed in such manner than an auxiliary blade b is laterally extended from a main blade a by sliding the auxiliary blade b along the main blade a as a result of extension and contraction operations of a hydraulic cylinder c, thereby to vary the blade length. In the case where an edge portion d of the movable auxiliary blade b and an edge portion f of a cutting edge e of the main blade a are tapered in the same direction as shown in FIG. 1, although no problem arises in varying the blade length, the knife edges of the movable auxiliary blade b and the cutting edge e do not align on the same straight line but a step is formed therebetween. Hence, when the blade assembly is tilted (when the scraping angle is varied), a step is formed on a finished surface after the blade working operation, so that an adverse effect results.